Read from the World of Warcraft client build files.
How Arcane Defender's Wristguards Compares
Who It Suits
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Arcane Defender's Wristguards suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
Transmog Sets
Arcane Defender's Wristguards is part of the transmog set Leyline Defender's Sunplate Armor (Warrior, Paladin and Death Knight only). The other 16 pieces:
Items Numbered Next to Arcane Defender's Wristguards
Blizzard numbers items as they are created, so the named items next to ID 134274 (134269 to 134281) were usually added in the same batch as Arcane Defender's Wristguards: the same quest line, zone, vendor or reward set.